Spyware is malware that secretly monitors a user’s activity and collects personal data – messages, calls, location, passwords, photos or browsing history – and sends it to a third party.
How spyware works
Spyware ranges from simple programs to highly sophisticated surveillance platforms:
- commercial spyware such as NSO Group’s Pegasus or Intellexa’s Predator, sold to governments and installed through zero-day exploit chains, sometimes without any click from the victim;
- stalkerware – apps that a partner or relative installs on a phone to read messages and track location;
- criminal spyware, including keyloggers and infostealers, aimed at passwords and money;
- adware and aggressive tracking that collect browsing behaviour for advertising.
Once installed, advanced spyware can activate the microphone and camera, read end-to-end encrypted chats directly on the device and delete itself on command.
Why spyware matters for security
Investigations by Citizen Lab and Amnesty International have found commercial spyware on phones of journalists, activists, lawyers and politicians in dozens of countries. Apple and Google regularly patch zero-days exploited by such tools, and Apple sends threat notifications to targeted users. Stalkerware is a serious threat in cases of domestic abuse. For businesses, spyware on an executive’s phone can leak negotiations and trade secrets.
How to protect yourself
- Install system updates immediately and reboot your phone regularly.
- Install apps only from official stores and review permissions and device admin rights.
- High-risk users can enable Apple Lockdown Mode or Android Advanced Protection.
- If you suspect stalkerware, seek help from specialized organizations before removing it, as removal may alert the abuser.
